This invention relates to a board-to-board connector which is usable in a small electronic apparatus such as a mobile telephone, a mobile terminal, and a digital still camera.
In the manner known in the art, such a small electronic apparatus comprises an LCD board and a main board which are electrically connected to each other. For connecting the LCD board and the main board to each other, proposal has been made as follows.
Referring to FIG. 1, a board-to-board connector comprises an elastomer connector 20 for electrically connecting a first or LCD board 21 and a second or main board 22 to each other. The connector 20 comprises an insulator 23 having elasticity and a number of contacts 24 fixed on the surface of the insulator 23 at a predetermined interval. The insulator 23 is formed into a shape such that a part of a cylinder is coupled with a rectangular parallelepiped body. The first board 21 has a primary surface 21a and a secondary surface 21b opposed to the primary surface 21a. Electrode patterns 25 are arranged on the primary surface 21b at the predetermined interval. The second board 22 has a principal surface 22a on which electrode patterns 26 are arranged at the predetermined interval.
Referring to FIG. 2, the connector 20 is interposed between the first and the second boards 21 and 22 that are parallel to each other. In other words, the first board 21 is placed on an upper surface of the connector 20 while the second board 22 is placed on a lower surface of the connector 20 with a space left between the first and the second boards 21 and 22. In this state, the electrode patterns 25 and 26 are in contact with the contacts 24, respectively. Therefore, the electrode patterns 25 of the first board 21 are electrically connected to the electrode patterns 26 of the second board 22 through the contacts 24 of the connector 11.
However, the connector 20 is weak in contacting force per one terminal and unstable in contact resistance. Since silicone rubber is used as a material of the insulator, the profile deformation is great. It is therefore impossible to improve a positional accuracy. In addition, short-circuiting between the electrode patterns on the LCD board and short-circuiting between the electrode patterns on the main board are often caused to occur. Furthermore, durability is poor.